An additional question arising during the Turbo Inlet Elbow airflow testing was how an aftermarket inlet pipe might change the intake system performance compared to the Mk7 GTI stock accordion pipe.
For this short test four cases were evaluated; the first two used the APR turbo inlet elbow flowing into an adapter sized similar to the IS20/IS38 compressor housing, once with the stock accordion and then into the APR CF pipe.
The second two tests involved the Leyo Motorsport inlet elbow flowing into a larger adapter to simulate an aftermarket turbocharger housing, again using the stock accordion hose and then the APR CF pipe.
First the APR inlet elbow tests were conducted on the flowbench at a test depression of 28″ of H2O.
A slight gain in airflow versus the stock hose was measured, equaling approximately 1.9% gain in maximum CFM.
Next the Leyo Motorsport elbow with larger adapter was tested.
With the higher airflow achievable through the use of the larger adapter the Leyo case with APR CF pipe saw an airflow gain of 2.4% over the stock accordion case.
Summary:
Airflow gains through a partial intake system were measured using a flowbench when replacing the stock GTI intake accordion hose with an APR carbon fiber hose. Gains were observed to increase with higher airflow values. Maximum airflow gains of 1.9% and 2.4% were recorded during this test.